Office investors are beginning to trickle back into downtown Los Angeles as a rising number of residents, restaurants and glitzy entertainment options bring new zest to the city's once-overlooked core.

But the rebound in the office market downtown remains weak compared with the growth of the area's night life and residential population. The rise in office property values continues to lag behind the region's prime office markets in places like West Los Angeles, Santa Monica and Beverly Hills that still are favored by tenants and big investors.