(Adds details on Q4 forecast, shares)
Oct 18 (Reuters) - EBay Inc forecast current-quarter adjusted profit that was largely below analysts' estimates as the company continues to ramp up spending to tweak its e-commerce platforms.
The company's shares fell 4.4 percent to $36.3 in after-hours trading on Wednesday.
EBay forecast fourth-quarter adjusted profit of between 57 cents to 59 cents per share. Analysts on average were expecting a profit of 59 cents per share, according to Thomson Reuters I/B/E/S.
EBay also reported 168 million active buyers in the third quarter, compared with analysts' estimate of 171 million, according to data and analytics firm FactSet.
The company is investing heavily to revamp its platform as it seeks to woo shoppers amid stiff competition from Amazon.com Inc.
EBay's net income rose to $523 million, or 48 cents per share, in the third quarter ended Sept. 30, from $413 million, or 36 cents per share, a year earlier.
Revenue rose 8.7 percent to $2.41 billion, edging past analysts' estimate of $2.37 billion.
Excluding one-time items, eBay earned 48 cents per share, in line with analysts estimates.
(Reporting by Aishwarya Venugopal in Bengaluru; Editing by Sriraj Kalluvila)