1999 || Kitt Peak || Spacewatch || KAR || align=right | 3.0 km || |-id=258 bgcolor=#E9E9E9 | 45258 || || — || December 18, 1999 || Socorro || LINEAR || — || align=right | 6.4 km || |-id=259 bgcolor=#d6d6d6 | 45259 || || — || January 2, 2000 || Kitt Peak || Spacewatch || KOR || align=right | 4.3 km || |-id=260 bgcolor=#d6d6d6 | 45260 || || — || January 2, 2000 || Višnjan Observatory || K. Korlević || NAE || align=right | 7.6 km || |-id=261 bgcolor=#fefefe | 45261 Decoen || || || January 2, 2000 || Gnosca || S. Sposetti || — || align=right | 3.2 km || |-id=262 bgcolor=#fefefe | 45262 || || — || January 3, 2000 || Gekko || T. Kagawa || NYS || align=right | 1.9 km || |-id=263 bgcolor=#E9E9E9 | 45263 || || — || January 3, 2000 || Chiyoda || T. Kojima || EUN || align=right | 5.6 km || |-id=264 bgcolor=#E9E9E9 | 45264 || || — || January 4, 2000 || Višnjan Observatory || K. Korlević || — || align=right | 3.7 km || |-id=265 bgcolor=#d6d6d6 | 45265 || || — || January 4, 2000 || Kitt Peak || Spacewatch || — || align=right | 7.3 km || |-id=266 bgcolor=#d6d6d6 | 45266 || || — || January 4, 2000 || Prescott || P. G. Comba || KOR || align=right | 4.5 km || |-id=267 bgcolor=#fefefe | 45267 || || — || January 2, 2000 || Socorro || LINEAR || V || align=right | 1.5 km || |-id=268 bgcolor=#E9E9E9 | 45268 || || — || January 2, 2000 || Socorro || LINEAR || — || align=right | 2.4 km || |-id=269 bgcolor=#fefefe | 45269 || || — || January 2, 2000 || Socorro || LINEAR || V || align=right | 1.9 km || |-id=270 bgcolor=#fefefe | 45270 || || — || January 2, 2000 || Socorro || LINEAR || V || align=right | 2.8 km || |-id=271 bgcolor=#E9E9E9 | 45271 || || — || January 3, 2000 || Socorro || LINEAR || — || align=right | 3.6 km || |-id=272 bgcolor=#E9E9E9 | 45272 || || — || January 3, 2000 || Socorro || LINEAR || — || align=right | 4.1 km || |-id=273 bgcolor=#E9E9E9 | 45273 || || — || January 3, 2000 || Socorro || LINEAR || — || align=right | 7.3 km || |-id=274 bgcolor=#fefefe | 45274 || || —