Los Angeles ( CNN ) -- The National Basketball Association will proceed with a vote to force a sale of the Los Angeles Clippers , rebuffing an effort by co-owners Donald and Shelly Sterling to sell the franchise voluntarily , NBA spokesman Mike Bass said Friday . `` We continue to follow the process set forth in the NBA Constitution regarding termination of the current ownership interests in the Los Angeles Clippers and are proceeding toward a hearing on this matter on June 3 , '' Bass said . His announcement followed reports earlier Friday about how Donald and Shelly Sterling agreed to a voluntary sale of the NBA franchise as the league prepares a vote on a forced sale , according to a source familiar with the situation . The couple have an agreement to allow Shelly Sterling to do the negotiations , and there have already been discussions between her and the NBA , according to the source . Attorneys for the Sterlings , who earlier declined to comment about the couple 's effort for a voluntary sale , were n't immediately available to react to Bass ' statement . The Clippers declined to comment on the NBA statements , spokesman Seth Burton said . Friday 's events signal how the NBA is standing by its ultimatum that a vote will be held on a forcible sale . For their part , the Sterlings appear to be running out of options -- short of suing the league -- and analysts say such a lawsuit would n't be inconceivable , as Sterling is an attorney well versed in litigation . Meanwhile , pressure grows for Donald Sterling , a real estate billionaire . He faces a deadline Tuesday to respond to the NBA 's proposal to terminate his ownership in the team because of racist remarks he made . The NBA has banned Donald Sterling for life , and the league is advancing a vote by other team owners that would force the couple to sell the franchise . The ban and pending vote -- along with a $ 2.5 million fine against Donald Sterling -- arise from how he slurred African-Americans . A voluntary sale would be a new maneuver for the Sterlings . Last week , Donald Sterling hired an antitrust lawyer to fight the NBA about the proposed forced sale . And his wife has said she wanted to keep an ownership stake in the team but does n't want to be the controlling partner . The couple own the team through a trust . They are also estranged , Shelly Sterling 's attorney has said . The NBA contends it was damaged by the 80-year-old 's racist remarks to associate V. Stiviano , 31 , that were captured on an audiotape and posted online in April by TMZ and in an interview with CNN 's `` Anderson Cooper 360Â° . '' `` Among other things , Mr. Sterling disparaged African-Americans and 'minorities ' ; directed a female acquaintance not to associate publicly with African-Americans or to bring African-Americans to Clippers games ; and criticized African-Americans for not supporting their communities , '' the NBA said in a recent statement . In order to terminate the Sterlings ' franchise rights , three-fourths of the team owners ( 23 of 30 ) would have to vote to sustain the charge and force a sale . Because Sterling is banned from any NBA activities , he is not allowed to vote , but the Clippers will have a vote , the NBA said . Report : NBA says Donald Sterling asked V. Stiviano to lie . NBA charges Donald Sterling , schedules June 3 vote . CNN 's Stephanie Elam and Jack Hannah contributed to this report .
NEW : Clippers decline to comment on NBA announcement . NBA will proceed with hearing on forced sale on June 3 . Comment: Donald and Shelly Sterling agree to sell Clippers voluntarily , source says .