Microsoft Corp.'s MSN unit is in talks to acquire wireless web ad provider Third Screen Media, the Wall Street Journal reported.

The potential acquisition of Third Screen Media shows MSN's interest in the growing mobile advertising industry. Current clients of Third Screen Media include USA Today and The Weather Channel.

Ovum, a technology consultancy firm, reports that mobile ad spending is expected to reach $1.3 billion by 2009.

Both companies declined to comment on the speculative talks.