By Akash Sriram (Reuters) -Warner Bros Discovery Inc is looking to cut up to 30% or nearly 1,000 jobs in its global advertising sales team, a person familiar with the matter told Reuters. The company on Tuesday started offering members of its U.S. advertising sales team an opportunity to voluntarily leave the company, the source said, adding that the global advertising sales team has about 3,000 members. The company’s finance chief Gunnar Wiedenfels in April reaffirmed its goal of achieving $3 billion in cost savings after a $43 billion merger between Discovery Inc and AT&T’s Warner Media. Wal…