SAN FRANCISCO (Reuters) -Apple CEO Tim Cook signaled on Thursday the iPhone maker was ready to spend more to catch up to rivals in artificial intelligence by building more data centers or buying a larger player in the segment, a departure from a long practice of fiscal frugality. Apple has struggled to keep pace with rivals such as Microsoft and Alphabet’s Google, both of which have attracted hundreds of millions of users to their AI-powered chatbots and assistants. Apple, in contrast, has leaned on outside data center providers to handle some of its cloud computing work, and despite a high-profile partnership with ChatGPT creator OpenAI for certain iPhone features, has tried to grow much of its AI technology in-house, including improvements to its Siri virtual assistant.